For a personal care item such as a razor, a razor blade cartridge has conventionally been proposed, which comprises a shaving aid containing a water-soluble resin such as a polyalkylene oxide attached to a portion of the razor blade cartridge made of plastic, in order to reduce the resistive force between a portion of a razor and the facial surface, etc., (for example, Patent Document 1).
It is known that a high-molecular weight compound (water-soluble resin) obtained by reacting a polyalkylene oxide compound and a diisocyanate with each other and having a weight-average molecular weight of 10000 or higher is used as a water-soluble solidified shaving aid (Patent Document 2).
A composite may be used as a smoother (lubricating agent) for wet shaving, wherein the composite comprises a water-swellable polymer swelling and releasing various aids upon immersion of the composite in water due to mixing of a water-soluble polymer (water-soluble resin) and the water-swellable polymer (Patent Document 3).
A polymer composite is disclosed as a polymer composite used in wet shaving instruments, medical instruments, etc., wherein the polymer composite comprises a water-insoluble polymer, and a water-sensitive copolymer (water-soluble resin) obtained by polymerizing an alkylene oxide monomer and an epoxy-functional monomer (Patent Document 4).